It was because her heart rate dropped. The monitor will alarm if her heart rate drops below 90bpm.
I dont think I had ever felt my heart leap out of my throat. I am used to it going off b/c the leads were loose. Its a long beep with an orange light. This time it beeped several times in a row and a red light by the low heart rate picture. I was asleep. I never want to wake up to a screaming machine with a red light again! DH was wtaching TV in the living room and came stomping down the hallway.
I turned on the lights to find her sound asleep and breathing. Thats considered a "self-resolve" since she didnt need stimulation from me in order to get her heart rate back up.
I am trying to figure out how it could have been a false alarm but its hard to tell. Her coloring was fine and she was breathing so thats all that matters. I think I am now okay with having this monitor until shes 6 months old, think I could keep it on her for life? =/